The use of latex coated with an antibody for detection of antigens has been known in the clinical art, and especially in the area of visible agglutinative reactions. The procedure is sufficiently specific and sensitive for accurate qualitative and quantitative determinations.
The art has recognized radioimmunoassay, agglutination, and enzyme immunoassay, in both direct and competitive binding assays. In the area of latex immunoassay, colored latex beads having specific antibodies bound to their surface, either chemically or by absorption, are used as a tag for antibodies. The so-called dipstick enzyme, or chemical immunoassay test, is used for rapidly qualitative and semi-quantitative information regarding the presence of analytes.
There has long been a need for a rapid and simple-to-perform procedure for distinguishing edible from potentially toxic fish; in particular, a procedure for detection of ciguatoxins and related low molecular weight polyether marine toxins in fish indigenous to regions where the ecological microflora which cause ciguatera are found. The major source of ciguatoxin is Gambierdiscus toxicus (G. toxicus) discovered in 1977 at Gambier Island, French Polynesia.
Ciguatoxin has been determined to be the major cause of ciguatera fish poisoning in the tropical and subtropical regions of the world. Ciguatoxin is a marine polyether that is synthesized by G. toxicus and then proceeds up the food chain through herbivorous fish and carnivorous fish (e.g., amberjacks, jacks, snappers, groupers, moray eels and barracuda). Ciguatoxin-4B (CTX-4B) from G. toxicus is converted to ciguatoxin-1 (CTX-1) in the moray eel liver.
Because more than 24 ciguatoxins (congeners) have been reported, it is unknown whether all species of carnivorous fish associated with ciguatera convert CTX-4B to CTX-1. Thus, a test procedure for analyzing suspect fish flesh should be capable of assessing all congeners and related polyethers of ciguataxin, such as maitotoxin, okadaic acid, brevetoxin and palytoxin, although the toxicity of the congeners may vary. These toxins, particularly ciguatoxin and its related polyether congeners, are able to maintain resinous and fatty substances in water suspension that are highly irritating in their pure form to the skin or mucous membrane.
If ciguatoxin is present in fish tissue or mucous membrane and consumed by humans, it can cause severe ciguatera food poisoning. Such poisoning may cause gastrointestinal, neurological and cardiovascular disorders, and a number of general symptoms. Possible gastrointestinal disorders are vomiting, nausea, stomach pains and diarrhea. Neurological symptoms may include paresthesia and dysesthesia. Cardiovascular effects include bradycardia and tachycardia. General symptoms include taste and vision alteration, itching, and weakness. The most severe general symptoms are muscle aches and joint pains, which may persist for months.
The present invention is directed to the field of analytical and immunological testimony, and more particularly, to an apparatus and method for testing organic extracts of organisms, vertebrate and invertebrate tissues, marine alga and microorganisms, using synthetic membranes in conjunction with antibody bonding assays and antigen-antibody reaction, especially with lipid epitopes. The reaction utilizes a solid-phase synthetic membrane in which extracted lipid fish toxins bind, and are then detected by antibodies coated onto colored latex beads giving the membrane the color of the beads. The unbound beads (coated with antibody) are then removed by washing in an aqueous solution.
The present invention has been made in view of the above-described inadequacies of the related art and provides a method for detecting ciguatoxin, its congeners and related polyether toxins in fish tissue prior to human consumption.
The present invention provides a method that is simple to perform and provides test results in a short period of time so that the method may be used on location by individuals to sort edible from potentially toxic fish.
The present invention also provides a field test kit for performing the method in accordance with the invention.
A preferred method for detection of ciguatoxin, its congeners and related polyether marine toxins in fish tissue comprises providing a support having a front face and a bottom face. The fish tissue is tested by immersing it into the solvent with the support. The support is removed after soaking with tissue in the solvent for a specified amount of time. The support is tested after it is removed and thoroughly dried. It is then immersed into the immunobead suspension containing mixed colored beads of two different diameters that are coated with anti-ciguatoxin, which is capable of recognizing ciguatoxin and related polyether marine toxins.
The results of the organic extract testing are analyzed by measuring the intensity of the color reaction in the support against a standard control of positive and negative tests.
These and further and other objects and features of the invention are apparent in the disclosure, which includes the above and ongoing written specification, with the claims and the drawings.